Portable, programmable medical devices are becoming more common and beneficial for treating patients. Some of these medical devices may be so small and lightweight that the patient is not confined to bed. In that case, the portable, programmable medical device gives the patient freedom to do some, if not all, of his/her normal day-to-day activities as he/she receives treatment. Other of these medical devices are readily moved about (i.e., portable), but still restrict the patient's freedom of movement. The device may include a controller that is programmed for controlling an operation of the device. With some portable and programmable medical devices, it is desirable to restrict the patient or other non-authorized person from deselecting the selected program or selecting another program during use.